(Received 27 November 2003)Beckmann rearrangement of
(Z)-cholest-4-en-6-one oxime (4)
(prepared in 4 steps starting from cholest-5-en-3b-ol (1)) with thionyl chloride in dioxane
solution afforded an enamide-type lactam, i.e.,
7-aza-B-homocholest-4-en-6-one (6)
as a single product. Photoreaction of the same compound in methanol or
benzene-acetic acid solution gave a mixture of products, with the
formation of the parent ketone 3
and the occurrence of Z/E
isomerization, while the lactam 6
was obtained only when the reaction was performed in methanol and then
in very low yield (7 %).

(Received
6 August, revised 21 November 2003)Abstract:
On the basis of quantum chemical (PM3 and RHF/6-31G*) study, the
regioselectivity of the bromination of
1-oxo-1,2,3,4-tetrahydronaphthalene (1)
and 6,7-dimethyl-1-oxo-1,2,3,4-tetrahydronaphthalene (2) at their alicyclic and aromatic
fragments was quantum chemically substantiated and confirmed
experimentally. It was found that the above compounds undergo aromatic
at the a-methylene position. The conditions for bromination at the
positions 5, 8 of benzannelated ring were established. For the first
time, non- and 2,2’-dibromosubstituted with respect to the oxo group
bis(6,7-dimethyl-1-oxo-1,2,3,4-tetrahydronaphth-2-yl) sulphides (7, 8a, b) were obtained. The latter
were found to show promise as stabilizing agents for the storage of
cholera sera.

(Received 6 August, revised 27 November
2003)An approach to the quantum chemical study of
"hydride ion" transfer has been proposed, according to which the
sequences of changes in ionization potentials, enthalpies and free
energies of the affinities to the hydride ion, to the hydrogen atom and
to the proton of substrates molecules and their derivatives (cations,
radicals, anions), are compared with the experimentally substantiated
series of "hydride" mobility. It has been established that the
experimental series of "hydride" mobility for six chalcogenopyrans
based on "semicyclic" 1,5-diketones is in conformity with the computed
ionization potentials of the molecules, and with the affinity of the
corresponding radicals to the hydrogen atom involved in the transfer.
The direct splitting-out of the hydride ion and the primary
deprotonation of the substrates followed by the withdrawal of two
electrons was elucidated to be unlikely. Feasible are the mechanisms of
"hydride" mobility, the first step of which consists of electron or
hydrogen atom transfer from the chalcogenopyrans molecules.

(Received
17 October 2002, revised 17 December 2003)A
series of acrylate functionalized samples based on hyperbranched
hydroxy-terminated polyesters with different molecular weights and
different degrees of acrylation were synthesized. The obtained urethane
acrylates were slightly yellow viscose liquids. Their composition was
characterized by FTIR and 1H-NMR spectroscopy and their
molecular weights were measured by GPC. All the synthesized samples
were diluted with 25 wt.% 1,4-butanediol dimethacrylate (BDDM). The
rheological properties of the uncured samples and the dynamic
mechanical properties of the UV cured samples were examined. All the
samples exhibit Newtonian behavior, which indicates the absence of
physical entanglements in these polymers. The viscosity increases with
increasing number of acrylic groups per molecule. The glass transition
temperature of the UV cured samples increases with increasing the
number of acrylic groups per molecule. The value of the storage modulus
in the rubber-elastic plateau and the cross-link density increase with
increasing number of acrylic groups per molecule. The formed networks
are inhomogeneous and the residual unsaturation is the highest in the
samples with the largest number of acrylic groups per molecule.

(Received
28 July 2003,
revised 8 January 2004)Macroporous crosslinked
poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate), p(GME),
was synthesized by suspension copolymerization and modified by reaction
of the pendant epoxy groups with ethylenediamine. The sorption rate and
capacity of the modified copolymer, p(GME)-en for Rh(III), Au(III) and
Pt(IV) ions were determined in batch experiments under non-competitive
conditions. The uptake of Rh(III) was faster than those of Au(III) and
Pt(IV). The sorption capacity for Pt(IV) was determined in the pH range
0.9–6.0. The maximum Pt(IV) uptake capacity onto p(GME)-en at pH 5.5
was 1.30 mmol/g.

(Received
11 August, revised 5 December 2003)The refractive indices of
ternary mixtures of chlorobenzene + n-hexane
+ (n-heptane or n-octane) have been measured at
298.15 K and at atmospheric pressure over the whole composition
diagram. Parameters of polynomial equations which represent the
composition dependence of physical and derived properties are gathered.
The experimental refractive indices and the ternary derived properties
are compared with the data obtained using several predictive
semi-empirical models. The use of the Soave–Redlich–Kwong (SRK) and the
Peng–Robinson (PR) cubic equations of state with the Van der Waals
one-fluid mixing rule, which incorporate different combining rules to
predict refractive indices on mixing, are tested against the measured
results, good agrement being obtained.

Faculty
of Natural Science and Mathematics, Department of Chemistry, University
of Nis, Visegradska 33, 18000 Nis, Serbia and Montenegro

(Received 22. September, revised 10 December 2003)A
kinetic-spectrophotometric method is proposed for the determination of
morin. The method is based on the inhibition effect of morin on the
oxidation of C6H5COONa by hydrogen peroxide in
the presence of the complex Fe(II)-AA(ascorbic acid), which acts as a
catalyst. The concentration range for the determination of morin is one
of the lowest achieved so far (a linear calibration graph was obtained
for morin from 2.255–22.55 ng cm-3). The limit of detection
of the method is 0.28 ng cm-3. The relative error ranges
between 1.42 to 5.10 % for the given concentration interval. Kinetic
equations are proposed for the investigated process. The effects of
certain foreign ions upon the reaction rate were determined in order to
assess the selectivity of the method. The major advantages of this
kinetic-spectrophotometric assay are its sensitivity, selectivity,
reproducibility, speed and simplicity.

(Received
12 September 2003, revised 19 January 2004)By using different
spectrophotometric methods, it was found that famotidine and
palladium(II) ions form a complex, Pd(II) : famotidine = 1:1, which has
an absorption maximum at 345 nm. The formation of the complex between
famotidine and palladium(II) chloride in Britton–Robinson buffer
solution in the pH range 2.23–8.50 was studied. The conditional
stability constant of the complex at the optimum pH 2.62 and ionic
strength 0.5 M was found to be log K’ = 3.742 ± 0.025. The Beer’s law
was verified over the famotidine concentration range from 5×10-5
– 6×10-4 M. The proposed method was
found to be suitable for accurate and sensitive analysis of famotidine
both as the substance (RSD = 1.02–1.80 %) and its dosage forms (RSD =
1.75–1.83 %).

(Received 29. October, revised 25 December 2003)LiNbO3
single crystals were grown by the Czochralski technique in an air
atmosphere. The critical crystal diameter Dc = 1.5 cm and
the critical rate of rotation wc
= 35 rpm were calculated by equations from the hydrodynamics of the
melt. The domain inversion was carried out at 1430 K using a 3.75 V/cm
electric field for 10 min. The obtained crystals were cut, polished and
etched to determine the presence of dislocations and single domain
structures. The optical properties were studied by infrared and Raman
spectroscopy as a function of temperature. With decreasing temperature,
an atypical behaviour of the phonon modes could be seen in the
ferroelectrics LiNbO3. The obtained results are discussed
and compared with published data.

This publication may be
viewed as an issue of Nova Acta Leopoldina, in particular its number
330 and volume 88, but (as this reviewer prefers) also as a separate
book. Anyway, it contains papers presented at a scientific conference,
held in Göttingen on October 11 to 13, 2001, under the auspices of the
German Academy of Natural Sciences Leopoldina, the Göttingen Academy of
Sciences, and the French Academy of Sciences, The book contains 8
articles (that this reviewer will refer to as chapters), preceded by in
introduction written by Herbert W. Roesky,In
the "Introduction" (pp. 7–9) Roesky recalls that a language is a system
of verbal signs which are typical for a community of people who want to
express what they think and who want to be understood by the other
members of the community. Because modern chemistry and mathematics
began... to discover that there are a lot of things they share, the
purpose of this conference was to bring chemists and mathematicians
together, in order that they could better understood each other. This
is best expressed by Peter Deuflhard, who, by studying the relations of
the scientific languages of chemistry and mathematics, concludes: The
common clear message from these comparisons is that chemical intuition
may pave the way for mathematical concepts just as chemical concepts
may gain from mathematical precisioning. Along this line, significant
improvements in chemical research and engineering have already been
possible -- and can be further expected in the future from the dialogue
between the two scientific languages.The
first chapter is "Chemistry as an Ideographic Language" by Guy Ourisson
(pp. 11-18). It briefly outlines the wealth of information contained in
a structural formula of an organic compound. What the paper does not
mention is that such formulas have also a mathematical content,
recognized already in the middle of the 19th century.The
second chapter "Transition Metal-Based Machines and Motors at the
Molecular Level" (pp. 19–38) is written by Jean-Paul Collin and four
coauthors. It contains exactly what the title says and is nothing but a
well–written (chemical) review article.The
next chapter is "Virtual Crystallography" by Olaf Delgado-Friedrichs
(pp. 39–49). It describes the author's original and interesting
combinatorial and geometric researches, related to crystallography.Follows
"A Comparison of Related Concepts in Computational Chemistry and
Mathematics" by Peter Deuflhard (pp. 51–66). This text goes to the very
center of the theme. It considers three mathematical concepts
(intrinsic low-dimensional manifolds, Galerkin's method for
constructing special Hilbert spaces, and geometrical conformations) and
connects them with three fields of physico-chemical research
(quasistationary state approximation in chemical kinetics, lumping in
polymer kinetics, and molecular conformational analysis).The
fifth chapter "The Essence of Chemical Thinking Beyond Mathematical
Equations" by Jerzy Haber (pp. 67–80) has the ambition to demonstrate
that chemistry is based on an interplay of theory, comprising
phenomenological inductive laws and deductive theory, experiments, and
chemical intuition, and that chemistry developed its own ideographic
language, whose semiotic rules permit to understand reaction
mechanisms. In spite of these abstract claims, the article mainly
outlines the author's own (experimental) research of catalytic
oxidation of hydrocarbons. A few philosophical thoughts are found only
at the end of the text, whereas mathematics is completely absent.The
next chapter is “Analysis of Chemical Reaction Systems – What Are
Mathematics Able to Do, How Far Has Chemistry to Help?” by Jürgen
Warnatz (pp. 81–108). It provides examples for how complex phenomena
encountered in chemical and industrial processes are modelled by
mathematical methods. These will be found interesting by both chemists
and mathematicians.The
"Poetic Suggestion in Chemical Science" (pp. 109–139), written by (Sir)
John Meurig Thomas, expresses some thoughts on the artistic and poetic
aspects of both mathematics and chemistry, richly illustrated by facts
and pictures from their past and present. Although the entire book is
full of high-quality and beautiful figures, this chapter is really a
piece of art. It would be good to make this article available to
high-school students, before they decide what they will be studying –
the number of those choosing chemistry would increase significantly.The
last chapter "Combustion: From Mathematical Models to Practical
Devices", by Jürgen Wolfrum (pp. 141–160), is a fine survey of the
physical chemistry of combustion, however with very few details on its
mathematical modelling.There
is a total of 218 references quoted in this book. Not a single one is
from the Journal of Mathematical Chemistry or MATCH Communications in
Mathematical and in Computer Chemistry, the only two journals devoted
to mathematics-related researches in chemistry. Not a single quotation
is from the Journal of Computational Chemistry or Journal of Chemical
Information and Computer Sciences or Computers & Chemistry, the
three main journals for publishing computer-aided researches in
chemistry. Not a single quotation is from Theoretical Chemistry
Accounts (former Theoretica Chimica Acta) or International Journal of
Quantum Chemistry, the leading journals for theoretical chemistry. This
says something about the modes by which the authors of the book were
invited or selected, and the connection of the contents of the book to
contemporary scientific activities, lying on the border between
mathematics and chemistry, sometimes referred to as Mathematical
Chemistry.In
spite of the above, there is no doubt that the book “Chemistry and
Mathematics: Two Scientific Languages of the 21st Century” is a
valuable attempt to improve understanding, communication, and
cooperation between mathematicians and chemists. From a technical point
of view, the book is a masterpiece.

Ivan Gutman Faculty
of Science, University of KragujevacKragujevac,
Serbia and Montenegro